Should mankind go back to the Moon?

What a waste of money! There is so much to be done on Earth that makes shooting for the Moon and the stars ludicrous. The first Moon shot was just part of the competitive sparring in the Cold War era. It led to no overall benefit to global society. Health, education and social equity are far more worthy causes. Don't be fooled by the concept that such challenges bring useful step changes in technology. Computers, mobile phones and digital TV would have happened without a space programme. And think how much of a carbon footprint a launch rocket leaves in its trail. Let's keep our feet firmly on the ground.

· Karol Sikora is a cancer specialist

Robin McKie

No; $100bn has already been spent on a space station that cannot support a full crew. A similar sum will be spent getting to the Moon to build a base there. Yet the scientific returns will be minimal, even if construction proceeds flawlessly. The same amount of money - spent on robot probes and space telescopes - would transform our understanding of the universe and allow us to seek signs of life on other worlds, in our solar system and around other stars. That is where the adventure lies. Returning to the Moon, to repeat the old successes, is a failure of nerve and imagination.

· Robin McKie is Science Editor of The Observer

Sunder Katwala

Curiosity-driven science is important in its own right to push back the frontiers of knowledge. We can't predict the medical or environmental gains it will bring, so a cost-benefit analysis is difficult, but there is a strong case for a space programme including research on the Moon itself, if that is what the scientists think makes most sense. The motivation needs to be right. The most urgent scientific cause of our age is climate-change. One worry is that some in America may see colonising the Moon or the planets as an alternative to saving this one.

· Sunder Katwala is general secretary of the Fabian Society

Barbara Gunnell

I'd like to go to the Moon and could offset the carbon for about £1,000 (but only by taking an ordinary passenger plane, fully booked). Isn't it a bit comic that Nasa's gung-ho announcement of a manned Moon base came just as the Iraq Study Group told President Bush that his current adventure, only a few thousand miles away on Earth, had been an abject failure? True, the Moon has no citizens to kick up at being invaded. But there's something tragically destructive about looking for new places to despoil. We should learn to respect the Earth before we take our bad habits elsewhere.